At a seminar in Union City's Ruggieri Senior Center, a panel described common scams and how to avoid them in home repair, medicine and most broadly, finance. Seniors are the most common target demographic for fraud, a fact the panel attributed to a willingness to help, the distribution of wealth favoring the elderly, and the overall trusting nature of older Americans.

"Financial fraud is the crime of the 21st century," said Dena Aindow, a consultant at the Alameda County District Attorney's office, who says that potential scammers count on, "the fact that [seniors] do engage and answer our phone."

Home-owner fraud is a major area or loss for senior citizens, according to the seminar. "If the job is $500 or more, in material and labor, you must have a licensed contractor," said Jane Kreidler, of the Contractors' State License Board. "Any type of licensing, they must have their contractors' license number," which Kreidler recommends people confirm with the board. "You need to get everything right," she said, recommending that home-owners get at-least three bids for a given project.

According to Kreidler, it's common for scam artists to go door-to-door advertizing their services for a small job or inspection, only to "discover" mold in the attic or other problems of that nature, and run up bills costing hundreds or thousands.

Some of the most famous scams involve the mail and, these days, email. Brian Markwell of the US Postal Inspection Service said, "We have been dealing with that since 1872." Markwell discussed such noted cons as the "grandson in Tijuana" and the "Nigerian prince" and warned seniors to verify the identity of anyone they talk to and never wire money to anyone they know. He also cautions people against scams related to checks, or even mistakes such as throwing out "convenience checks" from banks, which he says, are live checks. "When you're just cashing checks from other people, you can be held liable."

The current budget for Medicare is over $500 billion each year, 10% of which is lost through fraud, according to Pat Macholl of the Health Insurance Counseling and Advocacy Program. "A large area for fraud is durable medical equipment and ambulances," she said, as she cautioned seniors that even a TV commercial is no guarantee that a given plan or product isn't fraudulent, as TV doesn't vet the veracity of the ads.